/Engine/Plugins/FX/Niagara/Source/Niagara/Classes/NiagaraScriptSourceBase.h
Cause the source to build up any internal variables that will be useful in the compilation process.
virtual [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FNiagaraCompileRequestDataBase](API\Plugins\Niagara\FNiagaraCompileRequestDataBase), ESPMode::ThreadSafe > PreCompile ( [UNiagaraEmitter](API\Plugins\Niagara\UNiagaraEmitter) * Emitter, const [TArray](API\Runtime\Core\Containers\TArray)< [FNiagaraVariable](API\Plugins\Niagara\FNiagaraVariable) > & EncounterableVariables, [TArray](API\Runtime\Core\Containers\TArray)< [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FNiagaraCompileRequestDataBase](API\Plugins\Niagara\FNiagaraCompileRequestDataBase), ESPMode::ThreadSafe >> & ReferencedCompileRequests, bool bClearErrors )